The use of robotic manipulators has become increasingly widespread. A typical robotic manipulator comprises an arm having a gripping tool attached at its end. The arm positions the gripping tool adjacent to a work piece that is to be operated upon and a gripping surface on the tool engages the work piece. The arm and the gripping tool are typically driven to the proper orientation for the gripping operation using an external energy source. As is well known, common energy sources currently being used are hydraulics, air, and electricity.
Since both the arm and the gripping tool are externally powered, each time a gripping operation is to be performed power must be supplied to both the arm and the gripping tool. Due to the multitude of orientations that can be required in order to move a work piece, the design and manufacture of robotic manipulators can become quite complex. It would be desirable to reduce the complexity of construction of such robotic manipulators without diminishing their working capability. It would also be desirable to minimize the number of external energy sources required to drive a robotic manipulator through the various required orientations.
In an environment where several different sized and/or shaped work pieces are to be operated upon, it has been necessary to provide a plurality of dedicated tools to attach to the end of the robotic arm. Each time a new operation is performed, one gripping tool must be removed while a second one is subsequently attached to the robotic arm. This has two distinct disadvantages. First, the process cycle time is significantly increased each time a tool change is required. Second, several different tools have to be positioned in an area easily accessible to the robotic arm. Additionally, means have to be provided for easily interchanging tools. The result of using a plurality of single purpose tools is that the robotic manipulator requires a significant amount of space and is also limited by the number of times a tool change needs to be made. The problem of required space also limits the accessibility of the robotic manipulator in confined areas because the robotic arm must be long enough to reach each of the required gripping tools.